The present invention relates to refrigeration systems. More specifically, the present invention relates to refrigeration system sensing apparatus and methods.
Refrigerated display cases are widely used in supermarket and other retail venues to keep perishable items cool. Some refrigeration cases are equipped with sensing or monitoring equipment that determines malfunctioning refrigeration case components. For example, refrigeration case monitoring equipment can be used to detect fan failure, a blocked drain, burned out or faulty lights, an open refrigeration case door, and a blocked evaporator coil. Due to the potentially large number of doors, fans, and lights that are included in some refrigeration cases, the cost of the sensing or monitoring equipment can be significant. Monitoring equipment may also need to be resistant to electromagnetic interference (“EMI”) and/or radio frequency interference (“RFI”) from other electrical components in the refrigeration case, such as lighting ballasts. Additionally, monitoring equipment may need to be able to withstand constantly cold temperatures and exposure to moisture.